This invention pertains to a lumber sorter, and more particularly to such a sorter wherein flexible slings having releasable ends are used to form the bins for receiving sorted lumber.
Sling-type lumber sorters have been proposed in the past, and are in use. In these machines, lumber-receiving bins are each defined by a pair of laterally spaced flexible slings. Such slings are anchored at one set of ends to the sorter frame, and are mounted at their other set of ends on the frame through power-operated reels and the like, for taking up and paying out the slings so as to accommodate different sizes of loads of lumber.
When the lumber collected in the bin is released onto the usual underlying conveyor chains, the slings are relaxed to lower the lumber onto the chains, and an operator then approaches each end of the lumber collection and manually pulls the slings outwardly away from the lumber.
There are several serious problems with such a system. For one thing, manual clearing of the slings is dangerous and quite time-consuming. For another, obviously only two slings can be used to form each bin, since endo sling clearance of an intermediate sling would be impossible. In other words, such an intermediate sling would not be able to clear the chains supporting the lumber on either side of the sling. Hence, the minimum board length which can be held in a bin has been defined in the past by the distance between the two slings.
A general object of the present invention is to provide a unique sling construction, in the setting of a sorter of the type generally outlined, which takes these concerns and considerations into account in a very practical and satisfactory manner.
More particularly, an object of the invention is to provide a sling-type lumber sorter which completely obviates the dangers encountered heretofore with prior types of sling sorters, and which further enables an extremely speedy unloading operation for collected lumber.
Another object of the invention is to provide such a sorter wherein the bins are capable of receiving and supporting boards of different lengths, including boards having lengths which are less than the distance between the two outer or end slings that define the end limits of a bin.
According to a preferred embodiment of the invention, what is contemplated is a sorter in which flexible slings are used to define the lumber-receiving bins, each of these slings having a releasable end which is released at the time that it is desired to deposit or dump a load of boards. Means is provided for recapturing such freed ends of the slings so as to reform a bin for the later receipt of lumber.
From these general considerations concerning the proposed construction, it will be obvious that the danger existing in the past, with respect to an operator manually having to remove slings, is completely avoided. All that need be done to release a load of lumber is to relax the slings (through the usual reels which are provided for supporting one set of ends of the slings), so as to deposit the lumber onto underlying conveyor chains, with the releasable ends of the slings then released, whereafter the reels may be operated to take up the slings. In other words, with the invention it is not necessary for an operator to approach a stack of lumber during a releasing operation.
Further, with end-releasable slings contemplated, more than two slings may be used to define a bin, including intermediate slings. With the useability of such multiple slings, the distance between the two outer or end slings does not define the minimum board length which can be received and held by a bin. Thus, boards shorter than this distance may be held.
Another feature of the invention is that it can easily be incorporated in existing sling-type sorters without requiring significant modifications of the latter.
Still another feature of the invention is that the proposed apparatus is simple in construction, and presents few maintenance problems.
These and other objects and advantages attained by the invention will become more fully apparent as the description which now follows is read in conjunction with the accompanying drawings.